Optoelectronic Tweezers (OET) has been developed for parallel manipulation of single cells and particles for a variety of biological applications (Chiou et al. (2005) Nature 436(7049): 370-372.). For example Optoelectronic Tweezers (OET) has been developed for dynamic manipulation of single cells and particles (Chiou et al. (2005) Nature, 436(7049): 370-372). OET can be used for trapping and manipulation of semiconducting and metallic nanowires (Jamshidi et al. (2008) Nature Photonics, 2(2): 86-89), micro/nano beads (Ota et al. 92013) Nano Letts., 13(6): 2766-2770; Glaesener et al, (2012) Optics Letts., 37(18): 3744-3746; Zarowna-Dabmwska et al. (2011) Optics Express, 19(3): 2720-2728), DNA (Jamshidi et al. (2009) Nano Letts., 9(8): 2921-2925), and biological cells (Jeorrett et al. (2014) Optics Express 22(2): 1372-1380; Shah et al. (2009) Lab on a Chip, 9(12): 1732-1739).
In a typical OET setting, large numbers (e.g., over 15,000) of individually addressable light traps can be formed across an area of 1 mm2 in low conductivity media (˜0.01 S/m). However, the utility of OET has been bottlenecked by its incompatibility with physiological buffers and low manipulation throughput. Previously, vertical phototransistor-based OET (Hsu et al. (2010) Lab on a Chip, 10(2): 165-172) has been proposed to address the buffer incompatibility issue. Low throughput, however, remains a major issue for all optical manipulation technologies, including, but not limited to OET. This fundamental limitation comes from the trade-off between field-of-view (FOV) and optical resolution. Large FOV, in general, means using lenses with low numerical aperture (N.A.). Such low numerical aperture lenses, however, cannot provide the required optical image sharpness to create a light intensity gradient that generates sufficient trapping forces. This is true for both direct optical forces in optical tweezers and light-induced DEP forces in OET. Consequently, large-area optical manipulation of single cells or particles is nearly impossible even with high-power light beam.